The input data is not a complete block. with AES

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When i am decrypting using AES algorithm i am getting the The input data is not a complete block.
error.
Following is the code:

C#

base64StringToDecrypt="dHQ4eeglPQ";
public static string DecryptString(string base64StringToDecrypt, string passphrase)
{
    //Set up the encryption objects
    using (AesCryptoServiceProvider acsp = GetProvider(Encoding.Default.GetBytes(passphrase)))
    {
        acsp.Mode = CipherMode.CFB;
        base64StringToDecrypt = base64StringToDecrypt.Trim().Replace(" ", "+");
        if (base64StringToDecrypt.Length % 4 > 0)
            base64StringToDecrypt = base64StringToDecrypt.PadRight(base64StringToDecrypt.Length + 4 - base64StringToDecrypt.Length % 4, '=');
        byte[] RawBytes = (Encoding.Default.GetBytes(base64StringToDecrypt));

     
     //   byte[] RawBytes =  Convert.FromBase64String(base64StringToDecrypt);
        ICryptoTransform ictD = acsp.CreateDecryptor();
      

        // Return decrypted bytes as a string  

        //RawBytes now contains original byte array, still in Encrypted state

        //using (MemoryStream ms = new MemoryStream())
        //{
        //    using (var cs = new CryptoStream(ms, ictD, CryptoStreamMode.Write))
        //    {
        //        cs.Write(RawBytes,0,RawBytes.Length);
        //        //using (var swEncrypt = new StreamWriter(csEncrypt))
        //        //{

        //        //    //Write all data to the stream.
        //        //    swEncrypt.Write(plainText);
        //        //}
        //    }
        //}


       // Encoding encoding = Encoding.UTF8;
      //  MemoryStream msD = new MemoryStream(RawBytes, 0, RawBytes.Length);
       
        //Decrypt into stream
        MemoryStream msD = new MemoryStream();
        CryptoStream csD = new CryptoStream(msD, ictD, CryptoStreamMode.Write);
        csD.Write(RawBytes, 0, RawBytes.Length);
        csD.Close();
        Encoding encoding = Encoding.UTF8; 
        return encoding.GetString(msD.ToArray());
        //csD now contains original byte array, fully decrypted

        //return the content of msD as a regular string
       // return (new StreamReader(csD)).ReadToEnd();
    }
}

please help me out...what i am doing wrong

Posted 15-Mar-13 0:37am

spydeehunk

Updated 14-Jun-14 1:04am

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

v2

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Bernhard Hiller · Answer 1 · 2013-03-15T00:52:00

Solution 1

Check the number of bytes found in the array RawBytes: it must me be a multiple of the number of bytes of your key (your variable passphrase). And the key ought to be 128 or 256 bits (16 or 32 bytes).

Posted 15-Mar-13 0:52am

Bernhard Hiller

guru bhai 1 · Answer 2 · 2014-10-27T23:51:00

C#

INPUT DATA IS NOT A COMPLETE BLOCK........... using AES

CSS

protected void PerformDecryption(ICryptoTransform decryptor, string inputFilePath, string outputFilePath)
			{

				//Open both the input file for reading, and
				//  the output file for writing.
				FileStream reader = new FileStream(inputFilePath, FileMode.Open, FileAccess.Read);
				FileStream writer = new FileStream(outputFilePath, FileMode.OpenOrCreate, FileAccess.Write);

				//Create an Encrypted Stream using the "encryptor" we created above
				System.Security.Cryptography.CryptoStream decryptedStream = new System.Security.Cryptography.CryptoStream(writer, decryptor, CryptoStreamMode.Write);

				byte[] bites = new byte[1024]; //Stores 1 KB
				Int32 bitesRead = 0; //Number of Bytes read
				Int64 totalBites = 0; //Total Number of Bytes read

				//Loop through the entire file reading 1 kb at a time
				while (!(totalBites >= reader.Length))
				{

					bitesRead = reader.Read(bites, 0, 1024); //Read the bytes from the input file.
					decryptedStream.Write(bites, 0, bitesRead); //Write the encrypted bytes to the output file.

					totalBites += bitesRead;

				}

				//Close and release streams:
				decryptedStream.Close();
				decryptedStream.Dispose();

				reader.Close();
				reader.Dispose();

				writer.Close();
				writer.Dispose();

			}